Jointer knife setting gauge



June 16, 1953 H. R. MccORMlcK 2,641,847

JOINTER KNIFE SETTING GAUGE Filed May 5, 1951 l I l u nnnnnnnnnnnl=| 4 INVENTOR HAROLD R. Mc CoRmcK I v I 20 2| I 24 I BY v ATTORNEY Patented June 16, 1953 UNITED STATE PATENT OFFICE 3 Claims.

My invention relates to a gauge for use in setting the knives or jointers, and the like.

It is exceedingly difficult to set the knives in a jointer head in absolute tangential alignment with the fixed or rear table of the jointer, and unless the knives are so set they cannot produce efficient work. In the majority of jointers or planers in use today, the task of sharpening and resetting the knives is complex and exacting, and the sequence of operations involved is roughly as follows. First, each knife is removed from the cutter head and sharpened, and the knives are then replaced in the head manually and a rough preliminary gauging of the knives is carried out during the initial tightening of the knife set screws. After this, through the use of a straight edge or other suitable gauge, the knives are gradually adjusted into proper position with relation to the rear table of the machine, by means of pressure, pounding or adjusting set screws, provided for that purpose in the cutter head. After final tightening of the knife clamping set screws, a final check with a straight edge or gauge is made to assure that the final tightening of the set screws has not caused displacement of the knives. It is frequently necessary to realign one or more knives when this final check is made.

It is a primary object of this invention to provide a highly simplified gauge device which will reduce to a single simple operation the previously discussed complex task of setting the jointer knives after sharpening them.

A further object of the invention is to provide a jointer knife setter gauge which will enable an unskilled workman to set the knives in a jointer head so that every knife and every portion of the edge of every knife will travel in a perfectly cylindrical path about the axis of the head in tangential alignment with the rear table of the jointer.

A further object is to provide a gauge device of the above-mentioned character which may be used for setting jointer knives of various lengths, widths and thicknesses.

A further object is to provide a jointer knife setter gauge which simultaneously holds the Y sharpened knife with a vise-like action, positions to manufacture.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a plan viewof a jointer knife setting gauge embodying my invention and having a jointer knife clamped therein,

Figure 2 is a fragmentary longitudinal vertical section through a conventional jointer and illustrating a side view of the knife setting gauge as it would appear in use thereon,

Figure 3 is a central vertical longitudinal section taken on line 3--3 of Figure 1 and showing portions of the jointer, for the purpose of illustration,

Figure 4 is an end elevation of the gauge as illustrated in Figure 1, part broken away, and

Figure 5 is afragmentary side elevation of the gauge in use with a different type jointer head.

In the drawings, where for the purpose of illustration is shown a preferred embodiment of my invention, the numeral iii designates generally a gauge block or body, preferably formed of cast steel, or the like, and accurately ground to produce a perfectly fiat bottom surface H. The gauge block ll? has substantial thickness, as shown, so that it will be subject to no bending or deflection. The gauge block is preferably divided with a large opening l2 near its rear end to materially lighten the same and the gauge block has a large rectangular recess 13 in its forward end, as shown. The provision of the openor sections l4, rear and intermediate transverse bars Hiand i6, and forwardly extending parallel longitudinal arms [1, all integrally joined, as shown. The overall width of the gauge block I 0 is preferably about three inches, and its overall length may be approximately three and onehalf inches, although these dimensions may be varied as desired. The forward ends 58 of the arms I! are beveled or inclined at an angle of approximately 30 degrees to the vertical, Figure 2, which is the knife angle of most conventional jointers. The inclination or angle of the ends l8 may, however, be varied as desired correspond ing to variations in the knife angles of certain commercial machines.

the arms I! by means of screws 20, engaging in screw threaded openings formed in the forward 'ends of the arms IT. The fixed jaw or plate I9 has its lower longitudinal edge projecting below the lower face I I of the gauge block, as shown at 2|, and the edge 2| is preferably beveled or in clined with respect to the opposite faces of the jaw I9, so that it is parallel with the lower surface I I of the gauge block. The lower beveled edge 2| forms with the inner side of the jaw I9 a sharp longitudinal corner or knife edge 22 which is maintained straight and true. The jaw I 9 is preferably about an eighth of an inch thick, so as to possess a high degree of rigidity, although this thickness may be varied if desired.

A movable transverse jaw or bar 23 extends between the arins ii and is shiftable longitudinally of these arms toward and from the fixed jaw I9. The movable jaw 23 is rectangular in transverse cross section, Figure 3, and is provided at its opposite ends with upper and lower longitudinal extensions or lugs M which slidably engage the upper and lower surfaces of the arms I? for guiding the jaw 23 along the arms. The movable jaw 23 has free sliding; engagement along the arms ll, but the contacting surfaces between the arms and movable jaw 25 are accurately ground and smooth so that the movable jaw 21: will not bind or deviate from parallel relation to the fixed jaw l9. As best shown in Figure 3, the movable jaw 23 is disposed vertically and has its lower longitudinal edge 25 disposed below the lower face H of the gauge block, and this edge 25 forms with the forward side 2% of the movable jaw 23 a longitudinal square corner 2? which is straight and true. The lower longitudinal edge 25 of the moveable jaw terminates a slight distance above the corresponding longitudinal edge 2i of the fixed jaw S. Ihe square longitudinal corner 27 of the movable jaw 23 is arranged in opposition to the innermost inclined surface of the fixed jaw I9, at a point just above the lower longitudinal edge The intermediate transverse bar it is provided at its longitudinal center and at the transverse center of the gauge bar it with a longitudinal screw threaded opening 2%, receiving an adjusting set screw 29, which is preferably an Allen head set screw. The forward end of the adjust.- ing set screw 29 engages the rear side of the movable jaw 23, at the longitudinal center of such jaw, as shown. toward the fixed jaw it and into clamping engagement with the jointer knife, the set screw 29 is tightened to securely clamp the movable jaw against the knife.

In Figure 2 typical portions of a conventional jointer are shown for the purpose of illustrating the use of my gauge, and such portions include the rear or fixed table with which the knives must be aligned, the front adjustable table 3|, jointer shaft 32 and jointer head 33 mounted upon the shaft 32 for counterclockwise rotation therewith. The numeral 3 3 designates a knife holding recess or slot in the head 33, within which is adjustably mounted a jointer knife clamping block 35, actuated by jointer knife clamp screws 36, having screw threaded engagement with the head 33. The jointer knife 3? to be set engages in the recess 3% between one side wall of the same and the clamp block 35.

After each jointer knife 3'! has been removed from the head 33 and sharpened, my gauge is employed to reset the knife with its sharpened edge in exact tangential alignment with the top of the rear table 3%. To do this, the'sharpened or beveled edge 38 of the knife 3'! is brought into When the movable jaw is shifted contact with the bottom faces of the arms I1 and directed upwardly, as shown. The beveled face 38 is now inclined with respect to the horizontal, as shown. The forward side of the knife 3'! lies flat against the inner side of the fixed jaw I9, and the movable jaw 23 is shifted toward the fixed jaw until its lower square corner 2? engages the rear side of the knife 3'5, just below its beveled face 3-8. The square corner 2? affords a firm grip on the knife 3?, and the knife is now clamped securely between the fixed and movable jaws by the tightening of the adjusting screw 29. The sharpened edge of the knife 3'! has bearing contact near its opposite ends with the lower ground faces of the arms 1?, and this assures that the knife will be in exact alignment with the top of the table throughout its entire length when set in the head 33.

The gauge block It is .now placed in the proper position upon the rear table 38, so that the blade 37 may enter the slot 34 of the head. The knife clamping screws 36 are now tightened against the clamping block 35, while the gauge block remains fiat against the table 31?. The adjusting screw 29 is now loosened, and the gauge is removed, and no further adjusting or gauging of the jointer knife is required. The sharpened edge of the jointer knife 37 is now in absolute alignment throughout its entire length with the top of the table 31 and this is the necessary condition for the jointer to operate efficiently.

It can now be seen that my gauge provides for the accurate and efficient setting of jointer knives with an absolute minimum of labor and little or no skill required to perform the operation. No separate or movable gauging devices are needed, after the sharpened knives are clamped in place upon the head 33, and the setting of the knives is completed when the gauge device is removed. The device is highly simplified in construction, light weight and extremely sturdy and durable.

In Figure 5 the gauge is illustrated in use with a slightly different type of jointer including a jointer head 39 having a knife receiving slot 40 which is narrower than the slot 35. Clamping set screws are provided which bear against the knife clamping block 35 to shift the same. into clamping engagement with the knife 3?. The set screws are operated with a screw driver from the outside of the head 39. In the type of jointer illustrated in Figure 2, the slot 34 is wide enough to accommodate a wrench for the head of the clamp screw 35. In either case, it can be seen that my gauge can be used effectively for setting the jointer knives, and no, parts of the gauge interfere with or develop a clearance problem with parts of the jointer.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention, or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A gauge device for use in setting jointer knives comprising a block having a fiat surface to rest upon a table of the jointer, the block having a recess in one end thereof forming a pair of parallel arms, the ends of the arms being beveled to an obtuse angle with respect to they fiat surface of the block, a plate secured to the beveled ends of the arms and extending between the arms and having one longitudinal edge extending downwardly below said flat surface of the block to form a fixed abutment, avbar extending between the arms and slidably engaging the same for movement longitudinally thereof toward and from the fixed abutment, one longitudinal edge of the bar extending downwardly below the fiat surface of the block and arranged in opposition to the fixed abutment, and an adjusting screw connected with the block and engaging the movable bar to hold the same in a selected clamping position.

2. A gauge device for use in setting jointer knives comprising a block having a fiat surface to rest upon a table of the jointer, the block 1 having a recess in one end thereof forming a pair of parallel arms, a plate secured to the ends of the arms and extending between the same and having a longitudinal edge projecting'below the fiat surface of the block and forming a fixed abutment,a bar extendingbetween the arms and connected therewith for movement longitudinally thereof toward and from the, fixed abutment, one

longitudinal edge of the bar projecting below the flat surface of the block and arranged in opposition to the fixed abutment, and adjustable means carried by the block and engaging the bar to hold the same in a fixed position with respect to the abutment. V

3. A gauge device for use in setting jointer knives comprising a block having a fiat surface to slidably rest upon a table of the jointer, said block having a width corresponding generally to the length of th knife to be set,v a member carried by one end of the block and projecting downwardly below the block to form an abutment when the flat surface of the block is resting upon the table, a second member slidably mounted upon the block in opposed relation to the first named member and shiftable toward and from the first named member and having a portion projecting below, the flat surfac of the block to form a second abutment when the block is resting upon the table, a portion of the flat surface of the block between the first named and second abutments engaging the knife to be set throughout substantially the entire length of the knife when the knife is introduced between the first named and second abutments, and adjustable means connected with said second member to move the second member toward the first named member for clamping the knife between the first, named and second abutments.

HAROLD R. MCCORMICK. 

